Cushioning means for engine starters



Jano 4, Fn f CUSHIONING MEANS FOR ENGINE STARTERS l original Filed Aug; 11, 1-943 lmwl ' INI/E N TOR.

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Patented Jan. 4, 1949 Frank Wright. Moreno, Calif., assigner toBreese Corporations, Inc., Newark, N. .1., a corporation of New Jersey Original application August 11, 1943, Serial No. 498,441. Divided and this application July 8, 1947, Serial No. 759,333

(Cl. 12S-179) 2 Claims.

This invention relates to improvements in starters for internal combustion engines, and is a division of Patent No. 2,429,863, issued October 28, 1947.

An object of this invention is to simplify the construction of starters by reducing the numberof parts, landso arranging the parts `as to be more readily accessible in assembling and disassembling, i

A further object of this invention `is to provide a cushioning device to receive the impact of the main moving part, preventing upsetting and consequent malformation of parts to the extent of impeding, even actually obstructing action thereof.

The invention consists of the construction, combination and arrangement of parts, as herein illustrated, described and claimed.

In the accompanying drawings, forming part hereof, are illustrated three forms oi' embodiment of the invention, in which drawings similar reference characters designate corresponding parts, and in which:l

Figure 1 is a longitudinal sectional view of a complete embodiment of the invention, showing a cushioning means to absorb the impact of the drive member.

Figure 2 is a side elevational view of an alternative type of cushioning spring.

Figurel 3 is a partial side, partial sectional view 2 Although `a stiff spring 22 is provided to oppose the power stroke of the piston Il, and return it to its 'ginitial position at the end of the stroke, it is not; possible to prevent occasional striking of the reciprocating parts against sta tionary parts.

Thus, for example, the flange 23 on the drive shaft il at times will strike the end of the stationary nut-like hub element 24, which supports the said drive member I1. The imp'act of this action will eventually deform the outer spline or threads 25, causing them to bind on the splines or threads 2B, and thus prevent rotation and reciprocation of the drive shaft I1.

The inner end of the drive shaft I1, striking aaginst the end 21 of the driven shaft I3, also becomes battered or upset, creating further binding, to the extent of preventing proper action of the engine starter.

These harmful conditions are overcome by the device shown in Figures 1 to 5, in which a thin walled cylindrical casing 28 is fastened by its outstandingl base flange 23 to the inner face of an abutment ring 30 formed upon the hub eleof the shock absorbing means shown in Figure 1, l

Figure 1, IIJ designates a. cylindrical base bracket` having a cylinder II attached thereto. ,The rear end of the cylinder Il is closed as at I2 and provided with a screw-threaded axial bore I3, by which is attached one or more housings I4. The housing I4 communicates with a circultous passage I5 by means of which the expanding gases are led into the cylinder Il. The gases bear ment 24.

The casing 23 has an inturned annular bead 3| at its end oppositeI the abutment ring 30.

Fitted to move freely within the casing 28 is a ange 32 of a plunger ring 33, movable over the peripheral surface of the internally threaded hub element 24. This ring 33 is provided with an inreaching annular flange 34 which clears the drive shaft I1.

Mounted to move freely within the casing 23, circumjacent the hub element 24, are a plurality of flat, highly elastic rings 35, such as synthetic rubber, having interposed therebetween rigid washers 36. The washers 33 are ofv a slightly larger diameter and of lesser thickness than the against a piston I6 secured to a driving member I1 within the cylinder Il. As the driving member I1 is urged forward, itrotates a driven inem-- rings 35, thereby constituting a stack of cushion elements seated at one end against the abutment ring 30 and at its opposite end in contact with the slidable flange 32. This ange 32 moves inwardly of the casing, under impact of the drive member I1, preventing its deformation by absorbing its energy at the end of the stroke.

From this it will be seen that the hammer-like blows of the drive shaft i1, including its head 23, are very materially cushioned, preventing damage to the splines and likewise to the stationary parts engaged by it. i

In the modification shown in Figure 5, a series lof inclined ilat springs 31 are contained witmn the casing 23. Each spring 31 is shaped as the frustrum of a cone, theirouter edges being in contact as at Il, while their inner edles abut one another. as at ll.

Figure 2 shows another spring device consistknown embodiments ot the invention, it is not f to be held as restrictive. but rather suggestive, within the scope of the annexed claims.

Having thus fully described the invention, what is claimed as new and desired to be secured by Letters Patent of the United States. is:

1. An engine starter comprising in combination, a gas expansion motor including a ilxed cylinder, a piston movable therein and a spring to return the piston to its Lfiitial position; a hollow drive shaft rotatably mounted in said piston, said shaft having coarse helical internal and external concentric screw threads, a stationary nut to engage the external threads, a clutch shaft to engage the internal threads to be driven thereby, a ilxed casing spaced circumjacent said nut, la plunger ring movable in said casing, and a. plurality of resilient elements disposed in said casing adapted to force said plunger ring outwardly to intercept said drive shaft near the termination of its outward stroke thereby to prevent malformation of the parts in contact.

2. An engine starter comprising in combination, a gas expansion motor including a ilxed cylinder. a piston movable therein and a spring to return the piston to its initial position; a hollow drive shaft rotatably mounted in said piston. said shaft having coarse helical internal and external concentric screw threads, a stationary nut to engage the external threads, a clutch shaft to engage the internal threads to be driven thereby, a fixed casing spaced circumiacent said nut, a plunger ring movable in said casing. and a plurality of flat elastic rings loosely confined in said casing and rigid washers interposed therebetween, constituting a stack of cushion elements urging said plunger ring into position to receive the thrust ot said drive shaft near the end of its outward movement thereby preventing damage to the threads in contact.

FRANK WRIGHT.

REFERENCES CITED The following references are oi record in the file of this patent: v

UNITED STATES PATENTS 

